Predict the century
one of the main goals of this research is to find chronological stylistic changes in symphonies. Can they be separated by century? And if so, what distinguished them?
As you can see in the results, the random forest algorithm does a pretty okay job in labeling the tracks. precision would typically be around 73-85 and recall would be around 76-85. However this does leave room for enhancements. On the next page we will find out what the most entropic features are.
RESULTS:
# A tibble: 3 x 3
class precision recall
<fct> <dbl> <dbl>
1 18th 0.762 0.8
2 19th 0.722 0.65
3 20th 0.762 0.8 Enhancements I
As you can see, the most important features are c05, G, c06 and danceability. Lets feed those to the classifier on the next page
Enhancements II
The results have now been improved by some percents
RESULTS:
# A tibble: 3 x 3
class precision recall
<fct> <dbl> <dbl>
1 18th 0.7 0.7
2 19th 0.652 0.75
3 20th 0.765 0.65Tempo Histograms
This picture shows the different tempi over the centuries of symphonical tracks. As is visible, the distribution remains somewhat the same over the years.
Tempograms
These are tempograms for two outliers (respectively): a symphony by P. Glass and a symphony by Gorecki. Both composers are known for their contemporary take on the symphony with Glass being a minimalist (repeating the same musical ideas over and over again with little variation). The latter being clearly visible in the tempogram that shows little to no variation in tempi. The same holds for Gorecki.
compare to self similarity
Here are two recordings of the same symphony; symphony no 1 by Prokofiev. The former being made by Bernstein, the last one being made by the ‘dutch national philharmonic orchestra’. As you can see the tracks are slightly different.
compare to self similarity II
### Histograms
Chordogram
Standard Deviation
Haydn vs. Ades: Ceptograms
To take a closer look at the symphonic corpus, we may consider Joseph Haydn as one of the centre points of classical symphonies and Thomas Ades’ symphonies as an outlier. The symphonies in question are: Symphony no. 44 mvt. I, Haydn and Asyla op. 17 mvt I, Ades. Both representing an extreme within the classical music: Haydn being extremely structured and Ades being fairly unconventional. These two graphs substantiate that contrast. As is visible, Haydn’s symphony is timbre-wise somewhat restricted and Ades’ symphony’s timbre is more scattered. This comes with no suprise: Haydn restricts himself to a (relatively) small 18th century orchestra, with little or no real variation through the movement. Thomas Ades on the other hand is known for his sudden outbursts, contrastive sections (long silences vs intense soundscapes etc.).
Haydn vs Ades: timbre-based self-similarity matrices
These two matrices respectively substantiate the previous claims. Haydn’s symphonies show little to no timbre variation. Thomas Ades’ however, does show a lot of variety in timbre.
Haydn vs Ades: chroma-based self-similarity matrices
From these two matrices it becomes very clearly visible how both composers handle structure. If we take a closer look at Haydn’s symphony we see a very clear and obvious structure. The first block (along the diagonal) represents the first material in a short exposition, the second block is the introduction of new material again. Now, in the third and the forth block, we see a literal repetition of these first two blocks. This is an indication of the classical tendency to literally repeat certain sections in a symphony. Thomas Ades is a modern composer. Modern composers are known for their freedom with respect to traditional structures and forms, as can be seen in his matrix. There may be some similarity, but there is no real pattern or structure. For example, in Haydn’s symphony the first blocks are of the same length. What both composers have in common however, is that the patterns from the matrix become blurrier as they move to the final section of their movement.
Introduction
In the world of classical music, there is a tendency to endlessly re-listen famous classical composers such as Mozart, Bach, Beethoven etc. These composers deserve to have their admirable reputation, however, this has as result that nearly 95 percent of all classical music played in concert halls are old works. What does this say about our corpus? In the next visualization, we show the correlation (Pearson’s R) between the popularity of a certain track, and the popularity of the accessory composer. This way it becomes visible how inclined people are to listen to symphonies from famous composers rather than from unknown composers.
Composer vs track
As is visible in the graph, the black line resembles a straight upwards trend. Which means there is a positive correlation between a composers popularity and the popularity of their symphonies. The total Pearson’s R amounts to 0.59 (approximately).
Discussion
The former visualization shows us that people tend to be more interested in famous composer’s symphonies, than those from unknown composers. From one perspective, this is expected because a composer’s popularity is probably calculated from their tracks’ popularity. But from another perspective would it be somewhat prejudiced to listen to a composer’s symphony purely based on their other works, disregarding the efforts of unknown composers.